Support is requested for the 2009 Gordon Research Conference on Motile and Contractile Systems to be held July 12- July 17, 2009 at Colby-Sawyer College in New Hampshire. The purpose of this conference is to encourage the transfer of ideas and information within the community of scientists who work at the forefront of cytoskeletal research, an area that has long been recognized as critical for understanding fundamental biological processes. Cytoskeletal elements are essential for life in eukaryotes, making central contributions to cell motility, cell signaling, membrane trafficking, cell division, cell polarity, and the development of multicellular organisms. Actin, microtubules and molecular motor proteins are important for many normal physiological functions including wound healing, pathogen-cell interactions, cell- mediated immunity and embryogenesis. Moreover, cytoskeletal defects underlie many pathological human conditions including musculoskeletal and neurodegenerative diseases, oncogenesis, respiratory diseases, infertility, congenital blindness, deafness and ciliaopathies. Understanding the molecular basis for these disease states stems directly from basic research discussed at this meeting. The 2009 conference will focus on dynamics of cytoskeletal elements in living cells, and the functions of these complexes in cell locomotion, intracellular transport of membrane-bounded vesicles and mRNAs, chromosome segregation and cell division, and cellular movement within living organism. Because of its breadth and interdisciplinary nature, the Motile and Contractile Systems Gordon Conference has continued to play a seminal role in the field, despite the proliferation of subspecialty meetings. Approximately 60 outstanding research scientists will make formal presentations in eight lecture/discussion sessions. About one-third of these presentations will be selected from the submitted abstracts to encourage participation by outstanding new investigators, postdocs and students. Conferees that do not make oral contributions will be encouraged to present their recent work in a poster format.